1.2 Brief History of Operating System Development

	The evolution of operating system software parallels the evolution of the computer hardware it was designed
	to control (Ann McHoes, and Ida Flynn, (2010)).
	The first generation of computers (1940-1955) did not need operating systems because each computer has
	a unique structure and purpose.
	Second-generation computers (1955-1965) were developed to meet the needs of users and government.
	These computers adopted the job scheduling features to improve the productivity by grouping the programs
	with similar requirements.
	Starting the mid-1960s, the third-generation computers emerged.
	These computers used multiprogramming systems where more than one program is executed
	simultaneously.
	During the late 1970s, the operating systems used the virtual memory.
	In the virtual memory system, the applications do not have to reside all their programs in the main memory.
	During the 1980s, the operating system was part of the hardware which called the firmware concept.
	In the mid-1990s, the Internet has emerged. Operating systems have to support web accessibility and e-mail.
	In the 2000s, the computer systems can run multiple operating systems in the same time.
	The object-oriented design paradigm has been applied in implementing the modern operating systems.